Fuel-feed pump for internal-combustion engines



March 31, 1925.

R. WALKER FUEL FEED PUIP FOR INTERNAL COMBUSTION ENGINES Filed Jan. 25, 1924 1: :AM It ll 11 o i 2m 4 i s I ,I A

' mega'b u Patented Mar. 31 I925.

lenses PATENT m= -ic nunoLr' ALKER, or vIEnn-Afnusriam.

Application filed January e5,,1924. I Serial No. sss szs.

Toa ll cub-(man?may concern? t p Be it known that I, Runoiir WALKER? a.

subject of the Kingdom of Great Britain,

residing at XI. 'Sinimeringer.Hauptstrasse 384-0, Vienna, Austria have invented Improvements in FueLFeedlBumps forInter- "naLCombustion Engines (for which an rap-v plication was filedin Austrim Sept. 4, 1 922,

and in Germany Sept.9,1922) of which the followinggis a specification V This invention =has for its robyect to provideuan improved fuel feed pump 1 013111- ternal combustion engines ofthe type wherein afreely movable suction valve arranged on the fuel pump piston; In an improved 7 fuel pump according to this invention the suction valve is operated; by the pump pistom and for this purposethe suetion'valve of, the pump is arranged to he moved or dragged along by theepump piston in'the suction and delivery strokes of; the latter,

. and the pump piston is undone, whereupon whereby the suction valve is respectively opened and mainta ned in its opened position, and closed and maintained inns closed posit-ion. This manner of operating the slice tion'valve allows of achieving an. exact measurement and regulation of the volume of the pump. I

The openingand closing of the suction valve is effected positively by the motion of the pump piston by the fact that the suction valve opposes resistance to its own movement, and this resistance is overcome'by the movement of the pump piston.

In a preferred constructionalform of the improvedpump the pump piston, in its suction stroke, engages the'suction valve in its open position with a stop, and carries or drags it along in its'opened positionpositively, tothe end of the pump pistonstrokel In the compression stroke of the pump'piston the engagement between the said stop delivery the suction valve is first closed, and then whilst in its closed position it is carried or draggedfto the other end of the pump piston. l I I The accompanying drawings illustrate a constructional example of the improved fuel pump according to this invention, wherein the suction valve mounted'in the pumppiston is operated positively by the motion of the stroke of the pumppiston; Referring to the figures in the drawing I s v Flgure 1 1s a vertical sectional view of a r outside.

through thei'pump cylinder and piston intthe V planeof the suction valve rod engaging clip.

Eigure '3 ista fragmentary elevation. part? 1y insect-ion, of the pump piston rrein'oved from ,the cvlinder. I r

.I n,the illustrate-d example, the fuel pump piston 2 workingin thefuel (pump cylinder 1 contains the suction valve 3 of the pump; the delivery valve 4. of the pump being mounted in the pump cylinder 1: Thedelivery valve 4: is automatic, whereas the suction valve 3is operated mechanically.

' The control of the suction valvef3 is effected by the toandfro motion of the .pump piston 2. The pump piston is driven by means of a cam 5 which cor-operates with an antifriction roller 6" suspended from the pump piston by means lever? in sucha manner that the pump piston is moved downwards bythe cam 5 in order to make t its suction stroke, whereas its compression is eifected automatically by means of a spring 8 acting upon the pump piston. The

opening of the suction valve 3 isproduced by the arrangement'that the suction valve along by'the piston.

In the illustrated example the valve rod 9 extends through the pump piston 2 down to a point 14 of the pump casing l where access can be had to the said point from the The valve rod which carries: a stop 11 at the said point, is fixed in a spring clip 10 mounted in the stationary cylinder 1 F1g.. 2) a The stop 11 for the pump piston 2 is preferably constructed in the form of anut on the valve rod, andiitcauses the valve 3 to be carriedalong by the pump piston. The amount of playdbetween the stopll and the piston 2determines the amount of lift of the valve 3. This lift can be adjusted by adjusting the stop 11. The closing of the suction valve during the delivery stroke of the pump piston is due to the fact that by reason of the valve rod 9- bein'g clipped by 'the' clip 10' the piston effects the closing of the valve by moving in the upward ,direotionraway from the stop 11.

In order to obtain a complete filling of the pump suction chamber and a uniform delivery at every speed, the pump piston 2 is constructed, in the illustrated constructional example, as a stepped piston the larger stage 15 of which is utilized as a suction stage during the upstroke of the pump piston with the result that the fuel is sucked from the storage casing 13 through suction passages 14 into the pump suction chamber 16, whereas in the down stroke of the piston the fuel is delivered through the open suction valve 3 into the delivery chamber of the pump. In the down stroke, the stop 11 acts as a device for closing the suction chamber of the pump. Owing to the sucking action of the larger-stage so much oil is delivered in excess that" a complete filling of the pump, even at its highest speed, is assured.

What I claim is:

l, A. fuel pump for internal combustion engines including a cylinder, :1 pumppiston having passages therein, a suction valve in said piston, a stem carried by the valve and extending through one of the passages in the piston to another of the passages through which latter the stem is exteriorly accessible, a stop carried by the accessible portion of the valve stem, and, a retaining device co-opcrating with the stem whereby the suction 7,

valve, on the suctlon and pressure strokes 4. 'A fuelpump as claimed in claim 1 characterized in that the stop carried by the valve stem is adjustable.

5. A fuel pump as claimed in. claim 1 characterized by the provision of a stepped piston having openings therein communicating with the passages, the larger step of the piston forcing the fluid drawn in through said openings then into the suction passage of the piston on the suction stroke of the small step, the lug closing the suction passage during the last mentioned suction stroke.

In witness whereof I have hereunto signed my name in the presence of two subscribing witnesses.

RUDOLF \VALKEB. Witnesses CARL COUDONLMI,

JAS. WV. SIMPERTON. 

